Galvanizing apparatus



Aug. 27, 1929. F, W` BROWN 1,726,336

GALVANIZING APPARATUS Filed March 14, 1928 2 Sheets-Sheet 1 N i IN ENToR Aug. 27, 1929.

F. w. BROWN GALVANIZING APPARATUS 2 4sheets-sheet Filed March 14, 1928 9W llllll Patented Aug. 27,' 1929..

FREND W.l BROWN, or roLLo, PENNSYLVANIA.-

GALVANIZING- APPARATUS.

Applicationled March 14, 1928. Serial No. 261,577.

My invention relates to pressure rolls and method of operating the same, and particularly to tensioning devices for controlling the pressure on coating or exit rolls. While the invention is applicable to exit lrolls in baths for coating sheet m tal, it is to .be understood that it may be used in coating any type of sheet naterial.

In coating sheet metal material with surfaces of protecting metal, the thickness of the coating should be maintained uniform.

Where the coating is applied too thinly, there is danger that small portions of the surfaces of the sheet metal are not covered with the coating material. Such' surfaces ,are easily attacked by air and other gasesand are rusted away. The uncovered portions of the sheet metal offer small openings for rust, which openings enlarge and eat along the sheet metal, undermining areas which have been thoroughly coated.

If the coating is applied too thickly, a con-r siderable amount of the coating material is wasted-and there is a tendency for the coating material to peel" oli' from the sheets if the latter are bent. As the thickness of the coating on most sheet metal plates is appliedin accordance with customers specifications, variations in the thickness ofthe coating are apt to be sufficiently great so that an appreciable quantity of the coated sheets is rejected by the customer. It is necessary to trim the portions of the sheets which do not have the proper thickness of coating material thereon, wit-h a resultant waste.

As the thickness of the coating layer is determined by the pressure of coating or-exit rolls disposed at or slightly above the surface of the coating'material in a pot or tank, the control of the pressure on the rolls is of considerable importance.

v Heretofore one of the exitrolls has been biased into engagement with the other roll byone or more levers to the ends-of which weights are secured. bur'ng the movement of the exit rolls slight varia ionsin the thick- .ness of the sheets, or the entrance and exit of sheets between the rolls, causes the weights to move upwardly and. downwardly,.respec tively. By reason of the moments of inertia of such weights, theydo not maintain a constant pressure on the levers. As the weights are jecked upwardly their moments of inertia exert too much pressure vupon the rolls, and after the Aweights are in motion they do not exert enough force until they again come to rest. During such periods of acceleration and deceleration the rolls are subjected to `varying pressures, with the. result that unequal distribution of the coating material on the sheets is had.

- It has heretofore been proposed to bias the exit rolls into firm engagement by the application of spring pressure.` However, it is practically impossible to `adjust separate springs located at the Opposite ends of such rolls to exert uniform pressure. Also the movement of the rolls into engagement with each other after' a sheet has moved frbm between them, has not been suiliciently quick to prevent a considerable amount of the coating material being carried by the faces of the rolls. The next sheet passing between the rolls is given too thick a coating until the excess coating materialcarried thereon has been remove v I provide fluid actuated means for maintaining the same pressure at both ends of the floating exit roll, whereby the thickness of the coating material on the sheets is maintained uniform throughout the breadth of the sheets. The Huid actuated means comprises a cylinder mounted at each side of the coating machine, with its piston bearing against one end of the floating roll. By the application of the same fluid pressure to the cylinders the uneven pressure ofthe rolls is substantially eliminated, and the'same pressure is obtained at both ends of the rolls.

'Ehe accompanying drawings illustrate the present preferred embodiment ,of my invention, in which Figure 1 is a side View, partially in elevar tion and partially in section, of an sheet metal coating machine lnvolved 1n my invention,

' and j Figure 2 is a broken plan view of the exit rolls, pressure regulating system, and the driving mechanism for the rolls.

Referring to the drawings, a pot or tank 2 for coating sheet material is mounted in a wallfl in co-operative engagement with yburners 5. A coating machine 6 is mounted within the pot2 and a driving mechanism 7 is mounted externally of the pot n the wall 4 in order that the machine 6 may be removed from the pot without disturbing the driving mechanism 7. The pot 2 is filled with a spelter 4bath 8 that covers the lower portion of the machine 6 and is kept at a'level near' thecenter line of the exit or coating rolls 9 and 10 of the machine 6,- Th@9xact position of the From the feed rolls the sheets are fed through a flux box 14 and a V-shaped guide 15' disposed below the level ofthe bath to a pair of driving rolls 16 and 17. rllhe rolls 16 and 17 are disposed substantially at the bottom of'the guide 15 and near the bottom of the pot 2. From the rolls 16 and 17 a guide 18 directs the sheets upwardly into engagement with the exit rolls 9 and 10. The. curvature of the guide 18A is such as to discharge the sheets in substantially a vertical direction. The exit rolls 9 and 10 discharge the sheets upwardly between a guide 19 and a conveyor drum 20. rllhe coated sheets are removed from the drum 20 by any suitable conveyornot shown.

The rolls 9--10, 12-13 and 16--17 are all' mounted on a frame 21 of the machine 6 whereby they are removable as a unit from the pot 2. For driving the several groups of rolls the driving mechanism 7 comprises a vpower shaft 22 on which bevel gears 24 and 25 are keyed. The shaft 22 is mounted on a frame 26 that is disposed at one side ofthe pot 2 :in order to permit movement of the machine 6 independently of the mechanism 7. The bevel gear 24 meshes with bevel gears 27 and 28, which are connected to shafts 29 and 30, respectively. The shaft 29 terminates in a worm 31 that meshes with a worm wheel 32 connected to the shaft94 of the roll 12. The connection between the worm wheel 34 and 'the roll 12 preferably comprises a coupling 35 for permitting the separation of the driving mechanism 7 from the machine 6 when the latter is removed from the tank 2. The roll 12 is provided with a gear 36 that meshes witha gear 37 on the roll 13 for driving the latter.

The shaft 30 terminates in a worm 38 that meshes with a worm wheel 39 mounted on a shaft 40. The shaft 40 is mounted in bearings 41 carried on an extension 42 of the frame l26. The shaft 40 terminates at the inner end in a gear 44 that overlies and meshes with a gear 45 carried at one-end of the roll 9. The

other end of the roll 9 is provided with a gear 4 46 that meshes with a gear 47 on the roll 10.-

The conveyor drum 20 is mounted on a shaft 48 that is carried by bearings 49 mounted externally of the pot 2. The shaft 48 is provided with a sprocket wheel 50 that meshes with achain 51 engaging a sprocket wheel 52 carried on the outer endof the .shaft 40.

The bevel gear 25 meshes with. a bevel gear in the. bath 8 and are removable therefrom as a part of the unit 6. I

lVith the foregoing construction it is possible to remove the machine 6 from the pot for inspection and repair andinsert another unit without disturbing the drivingvmechanism 7 other than to open the coupling 35 and move the machine6 far enough to the right as viewed in Figure 2 to separate the gears 25-54 and 44-45. -Y

The exit rolls 9 and 10 are mounted on a beam 6() constituting a portion of the frame 21. Shims 61 are placed between the necks 62 of the rolls 9 and shoulders 64 on the frame 21. IThe roll 9 .is otherwise free to float or move laterally along the beam 60. The shims 61 determine the movement of the roll 9 toward the center of the unit 6. The roll 1() is free to move along the beam 60 until it engages the roll 9. The length of the beams 60 is considerably greater than the space required for seating the rolls 9 and 10.

As the thickness of the coating on the sheet metal traversing the exit rolls 9 and 10 is determined in large part by the pressure exerted between the rolls 9 and 10, it is important that these rolls be held in firm engagement with each other along their entire length. For maintaining such pressure lt provide Huid kactuated cylinders 65 disposed at the opposite sides of the pot with their pistons 66 terminating in bearing plates 67 that exert a downwardly and inwardly directed pressure on the necks 68 of the rolls 10. The pressure eXerted Iby the cylinders 65 forces the rolls 10 against the beam 60 and into engagement with the lrolls 9. The same pressure also forces the necks 62 on the rolls 9 into engagement with the shims 61. The cylinders 65 are supported by shelves 69 carried by the wall v4.A The cylinders 65 are connected by pipe lines 70 of the same length cross-sectional area and number of turns and elbows to a T 71 in order that the Huid pressure at the T 71 shall he'transmitted equally to the cylinders 65. Fluid under pressure is supplied to the T 71 from a pipe line 72 through a regulating valve 74. The valve 74 is provided with a handle 75 for varying the pressure transmitted and with gauges 76 and 77- for indicating the pressure at the opposite sides of the valve. As the pressure applied at both ends of the roll 10 is the same, the rolls 9 and 10 exert uniform pressure through! out their entire lengths, thereby insuring a.' uniform thickness of coating material adhering to the surface of the sheet material as it traverses the exit rolls.

For increasing or decreasing the thickness of the coating on the sheet metal, the pressure in the cylinders 65 is decreased or increased, respectively. 4

Prompt engagement between the exit rolls after a sheet has left them is obtained by the use of luid pressure actuated cylinders, since there are no large parts to accelerate and since the fluid pressure exerted in the cylinders is constant regardless of the position of thepistons Q6. As the cylinders 65 exert pressure in but one direction, it is not necessary to pro vide exhaust lines for them.

- While l have illustrated and described the present preferred embodiment of my invention,l it is to be understood that various changes may be made in the invention Without departing from the spirit of the invention or,

the scope of the appended claims.

l claim:

1. In a galvanizing machine, a container having a bath of spelter therein, means for rolls for the sheet metal having relative lat-l eral movement, substantially similar cylinders disposed at the opposite ends of one of said rolls, pistons cooperating with v said cylinders and roll ends for controlling the positions of the latter, and means for supplying said cylinders with fluid under substantially similar conditions.

2. In a galvanizing machine, a container having a bath of spelter therein, means for directing sheet metal through the spelter, exit rolls for the sheet metal having relative lateral movement, substantially similar cylinders disposed at the opposite ends of one of said rolls, pistons cooperating With said cylinders and roll ends for controlling the positions of the latter, and means comprising a pressure regulator for supplying said cylinders with fluid under substantially similar conditions. y

In testimony whereof I have hereunto set my hand.

IFREND W. BROWN. 

